We have been making words plural that end in an ‘o’. For some words you add an s. For some words you add es.
We have not found a rule to help with these words.
We have however discovered that some foods need es on the end, eg. tomatoes, potatoes, mangoes.
We have discovered that some musical words just need s, eg. banjos, cellos, radios, videos, pianos, altos, concertos, calypsos